Powered Serving Jig and Winder Device for Bowstring

ABSTRACT

A powered serving jig and winder device for bowstring comprises a right angle gear train having a drive shaft and a first beveled gear fixed thereon and a hollow transmission shaft with a second beveled gear fixed thereon, the first beveled gear configured to drive the second beveled gear at a right angle. A gear train collar comprises a first drive shaft bearing and left and right transmission shaft bearings. A first and a second serving cam are fixed to the transmission shaft at either end and have at least two openings for attaching a serving jig therein. A modified serving jig comprises a bowstring groove and a serving cord guide recessed therein and at least two pins extending away from the jig in a parallel direction to the bowstring groove, the pins configured to allow the serving jig to attach to one of the first and second serving adapters.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the priority date of earlier filed U.S. Provisional Patent Application Ser. No. 61/390,674, filed Oct. 7, 2010 for Ben D. Blosser, incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Serving a bowstring refers to binding and covering the bowstring in serving cord in order to protect, strengthen and provide certain features to the bowstring. Bowstrings are often serviced to bind the fibers of a bowstring or to create looped ends or to create a notch in the bowstring. Bowstrings may also be serviced simply to temper use and normal wear of a bowstring and prolong its useful life.

However, commercially serviced bowstrings may not be readily available due to many sizes and types of bows on the market and the specialized needs of archery enthusiasts. Additionally, because bowstrings are made of increasingly complicated and sophisticated composite materials such as Dacron, Kevlar and specialized polymers and polyethylenes, specific service cord may therefore be needed to match certain types of bowstring. It is usually economically impracticable for merchants to stock more than the most common served bowstrings. Therefore, bowstrings are often custom served to varying models and types of bows and bowstrings available today.

Custom service of a bowstring may be done manually using a conventional serving jig but manual tools and methods not only limit the number bowstrings that may be produced but also cause fatigue and wear to the wrists and hands of the one producing the bowstring. However, powered serving tools often require large and immobile machines in long tracks in order to produce high quality servings. On the other hand, smaller and more portable tools and methods do not produce the high quality and economical results needed for today's archery enthusiasts.

SUMMARY OF THE INVENTION

A powered serving jig and winder device for serving a bowstring comprises a right angle gear train having a drive shaft orthogonal to a hollow transmission shaft. The drive shaft is configured to be received into a chuck of a portable drill. The disclosure also includes a left and a right serving cam. Each cam is configured to attach to a respective end of the transmission shaft and to define a hole coaxial with the transmission shaft. Each cam is also configured to interlock with a modified serving jig. The powered serving jig and winder device may further comprise a bushing disposed in the coaxial hole of each serving cam. The bushing is configured to protect the bowstring and serving cord from rotation of the cam around the bowstring and the serving cord.

The disclosed serving jig includes a serving cord train comprising a supply bobbin, two tensioning rods and a serving cord guide recessed in a bowstring groove formed in a body of the jig. The serving cord train is configured to supply serving cord from the bobbin between the tensioning rods and through the serving cord guide into the bowstring groove for serving cord around a bowstring. The modified serving jig also includes at least one of a pin extending from the jig and a hole defined therein. Each pin and hole are configured complementary to a hole and pin respectively defined in and extending from a serving cam of a powered winder device and thereby interlock the serving jig to the serving cam and align the bowstring groove on the jig coaxially with the hollow transmission shaft of the winder.

Other aspects and advantages of embodiments of the disclosure will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrated by way of example of the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a perspective view of a powered serving jig and winder device for bowstring in accordance with an embodiment of the present disclosure.

FIG. 2 depicts an elevational view of a bushing end of a serving cam in accordance with an embodiment of the present disclosure.

FIG. 3 depicts an elevational view of a serving cam bushing in accordance with an embodiment of the present disclosure.

FIG. 4 depicts a perspective view of a bushing adjacent to a transmission shaft in accordance with an embodiment of the present disclosure.

FIG. 5 depicts a transmission shaft, a beveled gear and a left and right bearing thereon and a left and right bushing adjacent thereto in accordance with an embodiment of the present disclosure.

FIG. 6 depicts an elevational view of the powered serving jig and winder device for bowstring in accordance with an embodiment of the present disclosure.

FIG. 7 depicts a perspective view of the prior art for a conventional serving jig.

FIG. 8 a depicts a bottom elevational view of the modified serving jig in accordance with an embodiment of the present disclosure.

FIG. 8 b depicts a lateral elevational view of a modified serving jig illustrating a mounting block attached thereto in accordance with an embodiment of the present disclosure.

FIG. 9 depicts an elevational view of the modified serving jig attached to the winder device for serving bowstring in accordance with an embodiment of the present disclosure.

FIG. 10 depicts a perspective view of a collar enclosure with mounting and lubrication holes therein in accordance with an embodiment of the present disclosure.

FIG. 11 depicts an end elevational view of the modified serving jig attached to the winder device illustrating the bowstring channel coaxial with the hollow transmission shaft in accordance with an embodiment of the present disclosure.

Throughout the description, similar reference numbers may be used to identify similar elements depicted in multiple embodiments. Although specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims appended hereto and their equivalents.

DETAILED DESCRIPTION

Reference will now be made to exemplary embodiments illustrated in the drawings and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Alterations and further modifications of the inventive features illustrated herein and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

The disclosed powered serving jig and winder device for bowstring can cut the time it takes to serve a bowstring in half due to the powered drive and the simplicity of operation. The final served bowstring is produced to the highest quality specifications possible because of the degree of control allowed in the disclosed unique and non-obvious design. Additionally, the disclosed device is very safe to use having a completely enclosed gear box and design free of snagging corners and catching surfaces. Furthermore, the present disclosure is economical to produce in mass due to the modification of a conventional serving jig in combination with the powered winder device.

FIG. 1 depicts a perspective view of a powered serving jig and winder device for bowstring in accordance with an embodiment of the present disclosure. The depiction includes a drive shaft 1, a first beveled gear 2, a transmission shaft 3, a second beveled gear 4, a gear train collar 5, a drive shaft bearing 6, a left transmission shaft bearing 7 and a right transmission bearing 8 (not depicted), a left serving adapter cam 9 and a right serving adapter cam 10. The gear train collar 5 may comprise a recessed geometry configured to receive an indicia sticker therein. The right angle gear train comprises the drive shaft 1 and the first beveled gear 2 fixed thereon and a hollow transmission shaft 3 with a second beveled gear 4 fixed thereon. The first beveled gear 2 is configured to drive the second beveled gear 4 at a right angle. The embodied gear train collar 5 comprises the drive shaft bearing 6 and the left and right longitudinal shaft bearings 7 and 8, the bearings configured to reduce frictional forces between the drive shaft 1, the transmission shaft 3 and the gear train collar 5. The first and second serving adapter cams, 9 and 10, are fixed to the transmission shaft at either end and have at least two sets of openings (reference numbers in FIG. 2 below) for interlocking a modified serving jig thereto. The perspective view shows the hollow configuration of the transmission shaft 3 and a coaxial hole 3 d therein. In the embodiment depicted, each serving cam 9 and 10 define a hole coaxial with the transmission shaft hole 3 d. A bowstring may be strung axially through the hollow transmission shaft and through both serving cams in order that serving cord may be served from a serving jig around the bowstring.

FIG. 2 depicts an elevational view of a bushing end of a serving cam in accordance with an embodiment of the present disclosure. The coaxial holes 9 d in a left serving cam 9 and a similar hole 10 d in a right serving cam 10 (not depicted) are nominally at least one of three times as large as a bow cam portion of served bowstring and approximately 1.30 times as large as an endloop portion of served bowstring. This diameter ratio limits vibrations of the bowstring being serviced and therefore reduces service gaps of the serving cord around the bowstring with respect to service through a larger coaxial shaft. FIG. 2 also depicts a bushing 11 comprising a bushing hole 11 d coaxial with the transmission shaft hole 3 d, a bushing chamfer 11 a and a bushing face 11 b. A serving cam chamfer 9 c for the bushing 11 and a chamfer 9 e for the screws or bolts ‘b’ are also formed in the serving cam 9 as depicted and similarly in serving cam 10 (not depicted).

In an embodiment of the disclosed powered serving jig and winder device, each cam may be configured to interlock with a serving jig and therefore further comprise at least one of a pin extending therefrom and a hole defined therein, each pin thereof configured complementary to a hole defined in the serving jig and a hole thereof configured complementary to a pin in the serving jig. Throughout the present disclosure, the term ‘interlock’ may define two or more things which engage with each other by overlapping or by the fitting together of projections and recesses therein. In an embodiment of the disclosure, holes in each serving cam 9 a and 9 b may be parallel with the coaxial hole in each cam. There may be two sets of two holes each as illustrated by holes 9 a and holes 9 b. A center of each hole in a set may be approximately 21.0 millimeters from a center of the coaxial transmission shaft hole 3 d (and therefore also the bushing hole 11 d) and 41.0 millimeters (d1) from the other hole on a non-diametric cord approximately 4.5 millimeters (d2) from the center of the coaxial hole. One hole set may be disposed approximately 9.0 millimeters (d3) from the other hole set.

Each serving cam may be comprised of a solid block of machined aluminum approximately 13.5 millimeters thick. A shape of a serving cam may include a rounded end rectilinear shape, a disk, an oval, an ellipse and any other cam-like geometry comprising at least one of an interlocking pin and hole. An outside edge of one serving cam to an outside edge of another cam may measure approximately 92.0 millimeters and an outside edge of one cam with a bushing to an outside edge of another cam with a bushing may measure approximately 93.5 millimeters.

FIG. 3 depicts an elevational view of a serving cam bushing in accordance with an embodiment of the present disclosure. The bushing 11 includes a chamfer 11 a, a bushing face 11 b and a bushing edge 11 c. The bushings may comprise one of delrin, nylon and like materials and composites thereof. The bushings are configured to minimize a frictional component between a bowstring and the transmission shaft especially as the bowstring exits the shaft. A powered serving jig and winder device for serving a bowstring may therefore comprise a bushing disposed in the coaxial hole of each serving cam, the bushing configured to protect the bowstring and serving cord from a rotation of the cam around the bowstring and the serving cord.

FIG. 4 depicts a perspective view of a bushing adjacent to a transmission shaft in accordance with an embodiment of the present disclosure. The bushing 11 includes a chamfer 11 a, a bushing face 11 b and a bushing edge 11 c and a bushing side 11 e. The diameter of the bushing hole 11 d may be smaller than the transmission shaft hole 3 d or it may be approximately the same. A smaller diameter busing hole may minimize contact between a bowstring and the transmission shaft. On the other hand, a larger bushing hole diameter may provide more contact between a bowstring and the transmission shaft and therefore more wear on the bowstring. A flat portion of the transmission shaft 3 f is configured to enable a set screw to fix a component onto the transmission shaft such as a serving cam and a beveled gear.

FIG. 5 depicts a transmission shaft, a beveled gear and a left and right bearing thereon and a left and right bushing adjacent thereto in accordance with an embodiment of the present disclosure. The transmission shaft 3 comprises an axially flat portion 3 f configured to enable a set screw ‘s’ to affix a component to the shaft. The bearings 7 and 8 are set into the collar (not depicted) and enable the transmission shaft 3 to turn in the collar with little friction there between. The beveled gear 4 is configured to rotate the transmission shaft as a beveled gear on the drive shaft (not depicted) rotates at ninety degrees to the beveled gear 4. The bushings 11R (right) and 11L (left) are affixed into respective serving cams (not depicted) which are themselves affixed to the transmission shaft via a set screw ‘s’ and are therefore adjacent the transmission shaft 3.

FIG. 6 depicts an elevational view of the powered serving jig and winder device for bowstring in accordance with an embodiment of the present disclosure. FIG. 6 includes at least all the elements of the device depicted in FIG. 1 though rotated nearly 180 degrees to the left. Additionally, the disclosed device may include a gear train enclosure or housing (not depicted) configured to enclose the right angle gear train and the gear train collar but leave the left and right serving adapters to rotate freely outside the gear train box. The elevational view clearly shows the oblong design of the serving cams on the left and right sides of the transmission shaft 3. The bolts ‘b’ may secure the housing to the collar 5 as depicted in FIG. 11 below. The screws ‘s’ may radially secure disclosed components to the transmission shaft 3.

FIG. 7 depicts a perspective view of the prior art for a conventional serving jig. The depiction includes a bowstring groove or seat 12, a serving cord guide or hole therein 12 a, tensioning rods 16 and 17, a serving cord spool 15 and a serving jig body 18. Methods in the prior art include seating a bowstring in the groove of the bowstring seat 12 and wrapping serving cord around the bowstring as it is drawn from the spool 15 and out from the guide hole 12 a in the seat 12.

FIG. 8 a depicts a bottom elevational view of a modified serving jig in accordance with an embodiment of the present disclosure. The disclosed serving jig comprises a bowstring groove 12 and a serving cord guide hole 12 a recessed therein and at least two pins 13 and 14 extending away from the jig in a parallel direction to the bowstring groove 12. The pins 13 and 14 are configured to allow the serving jig to interlock with one of the first and second serving cams 9 and 10. The pins 13 and 14 therefore include unattached chamfered ends. The disclosed serving jig also includes a knurled tensioning nut 19 for convenient replacement of the serving spool 15 (not depicted) on the spool shaft 20.

FIG. 8 b depicts a lateral elevational view of the modified serving jig illustrating a mounting block attached thereto in accordance with an embodiment of the present disclosure. The disclosed modified serving jig may comprise a serving cord train including a supply bobbin (not depicted), two tensioning rods 16 and 17, a serving cord guide 12 a recessed in a bowstring groove 12 formed in a body of the jig 18, the train configured to supply serving cord from the bobbin between the tensioning rods and through the serving cord guide into the bowstring groove for serving cord around a bowstring. The mounting block 21 is attached to the body of the serving jig 18. Pins 13 and 14 are set in the mounting block 21 on one end and configured to fit into the holes in the serving cams 9 and 10 of the powered winder device on a free chamfered end. The mounting block affixed on an inside surface of the serving jig may therefore comprise at least one of a pin extending therefrom and a hole defined therein, the block also comprises a notch for clearance from the bowstring groove.

In embodiments of the disclosure, the modified serving jig may comprise at least one of a pin extending therefrom and a hole defined therein, each pin configured complementary to a hole defined in a serving cam and a hole configured complementary to a pin in a serving cam and thereby interlock the serving jig on a serving cam to align a bowstring groove on the jig with the hollow transmission shaft. Where two pins extend from the mounting block 21 attached to the serving jig, the two pins may measure approximately 41.0 millimeters from center to center. Also, the two serving jig pins each may each extend approximately 18 millimeters from a side of the serving jig. The chamfered free end of each pin facilitates interlocution with a parallel hole in a serving cam.

FIG. 9 depicts an elevational view of the modified serving jig attached to the winder device for bowstring in accordance with an embodiment of the present disclosure. The disclosed device includes the drive shaft 1, the first beveled gear 2, the transmission shaft 3, the second beveled gear 4, the gear train collar 5, the drive shaft bearing 6, the left transmission shaft bearing 7 and the right longitudinal bearing 8, the left serving cam 9 and the right serving cam 10. The modified serving jig also includes the bowstring groove 12 and the serving cord guide 12 a recessed therein and the two pins 13 and 14 extending away from the jig in a parallel direction to the bowstring groove 12. The pins 13 and 14 are configured to allow the serving jig to interlock one of the first and second serving adapters 9 and 10. The serving jig further includes the spool bobbin 15, the tensioning rods 16 and 17, the body 18 and the mounting block 21 for the pins 13 and 14. The mounting block 21 is attached to the body of the serving jig 18. Also, not depicted, is the collar or gear box enclosure as discussed below in the FIG. 10 description.

FIG. 10 depicts a perspective view of a collar enclosure with mounting and lubrication holes therein in accordance with an embodiment of the present disclosure. The collar enclosure 22, also known as a gear box cover, encloses the gear train, a portion of the collar 5, drive shaft 1 and transmission shaft 3 and thus protects an operator from moving parts and also keeps lubrication applied to the gears inside the gear box or collar. The enclosed gear box also provides a design free of snagging corners and catching surfaces. The cover 22 defines the holes 22 a, 22 b and 22 c in the enclosure configured to allow the operator to apply grease or other lubricants to the gears. The cover also defines the holes 22 d, 22 e, 22 f and 22 g and similar holes in an opposing side of the cover, the holes configured for bolts or screws to secure the cover 22 to the collar 5.

FIG. 11 depicts an end elevational view of the modified serving jig attached to the winder device illustrating the bowstring channel coaxial with the hollow transmission shaft in accordance with an embodiment of the present disclosure. The bowstring groove 12 is seen lined up with the bushing hole 11 d coaxial with the hollow transmission shaft 3. The secured ends of the pins 13 and 14 are seen in the mounting block 21 which is attached to the modified serving jig 18. The serving jig 18 is thus interlocked with the left serving cam 9. The collar enclosure 22 is secured to the collar 5. The drive shaft 1 is available to be received into a portable drill chuck. The bowstring is depicted as a cross-hatched circle in an end view. Therefore, a bowstring may be strung through the transmission shaft 3 via the serving cams 9 and 10 (not depicted) and through the bowstring groove 12 and serviced by cord supplied on the serving jig as the serving jig is wound around the bowstring by rotation of the serving cams powered by a portable drill held by an operator.

The present disclosure therefore allows for tighter more uniform serving application on a bowstring that protects and strengthens the bowstring. The present disclosure allows an operator to service the bowstring from either end without removing the winder device or serving jig. When a bowstring is served by hand and an operator stops to take a break, a loose spot may be created which may cause serving separation in use of the bowstring. The disclosure enables high quality service of bowstrings to bind the fibers of a bowstring or to create looped ends or to create a notch in the bowstring. Bowstrings now may be economically serviced simply to temper use and normal wear of a bowstring and prolong its useful life.

Although the operations of the method(s) herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner.

And though specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims and their equivalents to be included by reference in a non-provisional utility application. 

1. A powered serving jig and winder device for serving a bowstring, comprising: a right angle gear train having a drive shaft orthogonal to a hollow transmission shaft, the drive shaft configured to be received into a chuck of a portable drill; and a left and a right serving cam, each cam configured to attach to a respective end of the transmission shaft and to define a hole coaxial with the transmission shaft, each cam also configured to interlock with a serving jig.
 2. The powered serving jig and winder device of claim 1, further comprising a bushing disposed in the coaxial hole of each serving cam, the bushing configured to protect the bowstring and serving cord from a rotation of the cam around the bowstring and the serving cord.
 3. The powered serving jig and winder device of claim 2, wherein the bushings comprise one of delrin, nylon and like materials and composites thereof.
 4. The powered serving jig and winder device of claim 1, wherein a coaxial hole in a serving cam is nominally at least one of three times as large as a bow cam portion of served bowstring and 1.30 times as large as an endloop portion of served bowstring to limit vibrations of the bowstring being serviced and therefore reduce service gaps of the serving cord around the bowstring with respect to service through a larger coaxial shaft.
 5. The powered serving jig and winder device of claim 1, wherein the right angle gear train further comprises a first beveled gear fixed on the driveshaft and a second beveled gear fixed on the transmission shaft, the first beveled gear configured to drive the second beveled gear at a right angle.
 6. The powered serving jig and winder device of claim 1, further comprising a gear train collar configured to fix the drive shaft at a right angle to the transmission shaft, the collar comprising a first drive shaft bearing and a left and a right transmission shaft bearing, the bearings configured to reduce frictional forces between the drive shaft, the transmission shaft and the gear train collar.
 7. The powered serving jig and winder device of claim 6, wherein the gear train collar comprises a recessed geometry configured to receive an indicia sticker therein.
 8. The powered serving jig and winder device of claim 1, further comprising a gear train collar enclosure configured to enclose the gear train, the collar, the drive shaft, the transmission shaft and the transmission shaft bearings.
 9. The powered serving jig and winder device of claim 1, wherein the gear train collar enclosure defines at least one hole configured to allow the application of a lubricant to the gears therein.
 10. The powered serving jig and winder device of claim 1, wherein each cam configured to interlock with a serving jig further comprises at least one of a pin extending therefrom and a hole defined therein, each pin thereof configured complementary to a hole defined in the serving jig and a hole thereof configured complementary to a pin in the serving jig.
 11. The powered serving jig and winder device of claim 10, wherein a shape of a serving cam comprises a rounded end rectilinear shape, a disk, an oval, an ellipse and any other cam-like geometry comprising at least one of an interlocking pin and hole.
 12. The powered serving jig and winder device of claim 1, wherein an outside edge of one serving cam to an outside edge of another cam measures approximately 92.0 millimeters and an outside edge of one cam with a bushing to an outside edge of another cam with a bushing measures approximately 93.5 millimeters.
 13. The powered serving jig and winder device of claim 1, wherein each serving cam is comprised of a solid block of machined aluminum approximately 13.5 millimeters thick.
 14. The powered serving jig and winder device of claim 1, wherein each beveled gear and each serving cam are attached to the transmission shaft via a set screw and the drive shaft bearing is attached to the drive shaft via a set screw.
 15. The powered serving jig and winder device of claim 1, further comprising a serving jig comprising at least one of a pin extending therefrom and a hole defined therein, each pin configured complementary to a hole defined in a serving cam and a hole configured complementary to a pin in a serving cam and thereby interlock the serving jig on a serving cam to align a bowstring groove on the jig with the hollow transmission shaft.
 16. The powered serving jig and winder device of claim 15, wherein the at least one of a pin extending therefrom further comprises two serving jig pins extending from a mounting block attached to the serving jig, wherein the two pins measure approximately 41.0 millimeters from center to center.
 17. The powered serving jig and winder device of claim 15, wherein the two serving jig pins each extend approximately 18 millimeters from a side of the serving jig and a free end of each pin is chamfered to facilitate interlocking with a parallel hole a serving cam.
 18. The powered serving jig and winder device of claim 15, further comprising a mounting block affixed on an inside surface of the serving jig, the block comprising at least one of a pin extending therefrom and a hole defined therein, the block also comprising a notch for clearance from the bowstring groove.
 19. A powered serving jig and winder device for serving a bowstring, comprising: a left and a right serving cam, each cam configured to attach to a respective end of a powered transmission shaft and to define a hole coaxial with the transmission shaft, each cam also configured to fit with a serving jig; and a bushing disposed in the coaxial hole of each serving cam, the bushing configured to protect the bowstring and serving cord from a rotation of the cam around the bowstring and the serving cord.
 20. A serving jig, comprising: a serving cord train including a supply bobbin, two tensioning rods and a serving cord guide recessed in a bowstring groove formed in a body of the jig, the train configured to supply serving cord from the bobbin between the tensioning rods and through the serving cord guide into the bowstring groove for serving cord around a bowstring; and at least one of a pin extending from the jig and a hole defined therein, each pin and hole configured complementary to a hole and pin respectively defined in and extending from a serving cam of a powered winder device and thereby interlock the serving jig to the serving cam and align the bowstring groove on the jig coaxially with a hollow transmission shaft of the winder. 